Celtic face a tricky test away at Bundesliga side RB Leipzig on Thursday, and MacLean joked he hoped the 'Hoops' get "pumped" by the German outfit.
The striker won the Scottish Cup with St Johnstone in 2014 and already knows how tight semi-finals can be.
MacLean, 36, remarked: "Hopefully they get pumped on Thursday night and lose a bit of confidence - and we will see what happens on Sunday.
"Of course you want all Scottish teams in Europe to do well. But I hope they have a hard game as that can help us, especially if it goes deep [into extra-time] on Sunday.
On his team's chances, he added: "If we've got something that we can hold on to and they're pushing us, we know we can go the distance.
"It was well documented in pre-season that the gaffer had us all in it together. It was tough, up and down those dunes but we all stuck together and we got through it.
"We feel fit and we can make it hard for teams. We are a side that can go toe-to-toe and fight with teams - but we can play a bit as well."